The concentration and composition of the carbohydrate-containing macromolecules of whole human brain from 18 to 85 year-old brain tissue will be determined. These substances include the heteropolysaccharide chains of glycoproteins, the glycosaminoglycans, and the gangliosides. The purpose is to ascertain whether qualitative or quantitative changes occur in these substances as a consequence of aging, and to accumulate sufficient materials in order to determine the structure of the heteropolysaccharide chains derived from glycoproteins. Human brain tissue from neurological normal human patients are extracted with chloroform-methanol or tetrahydrofuran to recover the gangliosides. The defatted residue is treated with papain to solubilize glycopeptides and glycosaminoglycans. Glycosaminoglycans are precipiated with cetylpyridinium choloride and analyzed to distinguish between the levels of chondroitin 4- and 5-sulfate, heparan sulfate, dermatan sulfate, hyaluronic acid and chondroitin. Glycopeptides that act as receptors for con A are separated by means of affinity chromatography (Con A-sepharose); this fraction will be subdivided to yield neutral and basic mannose-rich glycopeptides as well as an acidic phosphorylated mannose-rich glycopeptide. The sialoglycopeptides, which do not bind to Con A, will be separated by means of lectin affinity chromatography, gel filtration, and/or anion exchange chromatography.